In this example, you will learn to check whether a number entered by the user is positive, negative or zero. This problem is solved using if…elif…else and nested if…else statement.
To understand this example, you should have the knowledge of the following Python programming topics:
1. Source Code: Using if…elif…else
num = float(input("Enter a number: ")) if num > 0: print("Positive number") elif num == 0: print("Zero") else: print("Negative number")
Here, we have used the
if...elif...else statement. We can do the same thing using nested
if statements as follows.
2. Source Code: Using Nested if
num = float(input("Enter a number: ")) if num >= 0: if num == 0: print("Zero") else: print("Positive number") else: print("Negative number")
The output of both programs will be the same.
Enter a number: 2 Positive number
Enter a number: 0 Zero
A number is positive if it is greater than zero. We check this in the expression of
if. If it is
False, the number will either be zero or negative. This is also tested in subsequent expression.